The present invention relates to apparatus for dispensing liquid soap, normally in discrete small quantities or charges. Such dispensing apparatus is used, particularly for hygienic purposes, in public or institutional washrooms or the like or wherever there are a relatively large number of different users.
One such dispenser is disclosed in U.S. Pat. No. 4,149,573, assigned to the assignee of the present invention, the disclosure of which is incorporated by reference, and of which the present invention is an improvement. In the system of the '573 patent, a container is provided with a refill aperture which is dimensioned so that at equal pressures inside and outside said container liquid soap will flow therethrough only very slowly if at all. Thus, in refilling the container, a special squeeze-bottle type refill cartridge is used in order to force the soap through the refill aperture, the cartridge outlet being closed by a pierceable membrane which is ruptured by a piercing member adjacent to the refill aperture to permit the flow of liquid soap from the refill cartridge.
Another dispenser disclosed in U.S. Pat. No. 4,345,627, assigned to the assignee of the present invention, the disclosure of which is incorporated by reference, teaches a dispenser which used a refill cartridge in the reservoir of the dispenser. This was a significant change and also an important commercial improvement. With the advent of the American Disabilities Act, there is now a requirement that at least one soap dispenser in all public washrooms must be able to be operated with less than five pounds of force and must be able to be operated by a disabled person with damaged hands or fingers. The soap dispensing systems taught in the patents referred to above as well as in U.S. Pat. No. 4,018,363 also assigned to the assignee of the present invention, the disclosure of which is incorporated by reference, all require a pulling action in access of five pounds of force. Accordingly, the prior inventions while commercially very important, were not capable of meeting the present requirements of the American Disabilities Act.